javascript - Clean up nested RxJS observable subscriptions -

question:

in angular 2 app, there few layers of nested subscriptions rest api calls return observables. what's best way remove nesting?

background:

i need calculate similarity between job's skills , user's skills jobs. need save similarity percentage corresponding match document. there's one-to-many relationship between users , matches. also, there's one-to-many relationship between jobs , matches. update match need find id first.

code:

// makes request '/api/jobs' this.jobservice.getjobs().subscribe((jobs: job[]) => {   (let job of jobs) {      // determine similarity between job's skills , user's skills     let percentage = this.calculatepercentage(job.skills, this.currentuser.skills)      // makes request '/api/matches/?jobid=12345&userid=11111'     this.matchservice.getmatchforuserandjob(job._id, this.currentuser._id).subscribe((match: match) => {        // makes patch request '/api/matches/54321'       this.matchservice.updatematchpercentage(match._id, percentage).subscribe()     })   } }) 

example schemas:

job

{     '_id': 12345,     'skills': [         { 'name': 'skill 1' },         { 'name': 'skill 2' }     ] } 

match

{     '_id': 54321,     'jobid': 12345,     'userid': 11111,     'percentage': 100 } 

further questions:

is flatmap work in case?

is there better way update matches?